The invention relates to a snowboard, consisting of a board on which two bindings are mounted on the surface of the board, at a distance apart approximately corresponding to ⅓ of the board""s length. The board is designed with inwardly curving edge portions, the board having a greater width at both ends at the transition to the tips, and with a minimum width of 18 cm in the middle. The board has upturned tips, possibly with a slightly more moderate tip at one end.
At present snowboards are normally designed with a flat sole surface between the tips at both ends. For steering the board is edged and the weight distributed between the feet in the two bindings.
Alpine skiing is a field which is related to snowboarding. In Alpine pair skis it is known to have the sole surfaces designed with angled portions in partial areas of the sole surface.
Thus in Norwegian patent no. 172 170 there is disclosed an Alpine ski, of a pair of skis, which on a maximum 20 cm long front portion has a gliding surface which diverges upwards when the steel edge diverges outwards from the ski""s longitudinal axis. The object of this ski is to turn with the least possible loss of kinetic energy. In patent no. PCT/NO95/00030 there is disclosed an Alpine ski, which on a portion which is longer than 20 cm has a gliding surface which diverges upwards when the steel edge diverges outwards from the ski""s longitudinal axis. The object of this ski is to turn with the least possible loss of kinetic energy, but in this case with a more harmonious design than in that which is described in Norwegian patent no. 172 170.
In Norwegian patent no. 301 964, which corresponds to EP 748245 there is disclosed an Alpine pair ski with a flat first sliding surface and lateral surfaces provided with an almost continuous concave inward curve between a first transition line which defines the transition from a tip portion to a front portion and a second transition line which defines the transition from the main portion to a rear portion. The lower lateral edge between the transition lines describes an almost continuous curve. The sole on both sides of the first sliding surface comprises further sliding surfaces, which extend upwards from the edge of the first sliding surface to the lower lateral edges of the ski with an upward curve. The additional sliding surfaces extend in the longitudinal direction of the ski, at least from the first and second transition lines respectively towards a transverse line behind the middle of the ski and in the portion of the ski where the binding is attached, the width of the ski at the transverse line being equal to the least width of the ski between the transition lines. The upward curve in the lower lateral edge on the additional sliding surfaces increases substantially with the ski""s increasing width in the direction of the two transition lines.
An Alpine ski as described in this publication has been shown to be very well suited to Alpine events and the angled sliding surfaces, which even with a relatively slight edging of the ski can be pressed into contact with the base, giving improved turning technique and grip on the base.
The present invention is based on the development of Alpine skis which is described in Norwegian patent no. 301964. Even though both skis and snowboards are used for downhill skiing and turning in Alpine terrain, there are nevertheless significant differences. This difference is based both on the difference in design of the two products and on the manner in which the product maneuvers. In skis the weight is distributed with a foot in a binding in the central portion of each ski and the ski, which is elongated and relatively narrow, at least for most of its length, will, when a pressure load is applied in the central area, be able to be forced to assume different positions against the base. In the case of a snowboard the performer stands with both feet on a substantially wider board and he will steer the board by bodily movements and by distributing his weight between the front and the rear of the board. Since the board is wider and shorter and the weight distribution different the board will not only be more rigid than a ski but will also be steered in a different way.
In the present invention it has been found that a number of the principles which have been developed in connection with the ski according to Norwegian patent no. 301964 in modified and developed form can be employed for further development of a snowboard, resulting in a marked improvement in their handling characteristics.
On this basis, therefore, it is the object of the invention to provide an improved snowboard. This is achieved by means of a snowboard which is characterized by the features which will be presented in the patent claims.
The snowboard according to the present invention differs from the above-mentioned, known ski designs in the requirement, amongst other things, that the secondary lateral areas of the board should be substantially tapered. By being tapered it should be understood that the angle of the lateral area against the base, viewed in the transverse direction of the board, increases from the central portion up to the front area at the tips.
From the dynamic point of view a snowboard differs from a ski in many ways, for reasons of both design and mode of application, as indicated above. A ski with a certain inward curve will be twisted upwards at the tip and rear tip when edged, since the skier presses with his foot in the middle of the ski and the counter-forces from the base will twist the ski, reducing the aggressiveness at the front and the rear due to the fact that the sole is flatter against the snow at the front and the rear than in the middle. In contrast with this the performer on a snowboard will stand with both feet placed not so far from the tips, with the result that in relative and absolute terms the snowboard has less length than the ski to generate a twisting moment. It will therefore not be so easy to twist the snowboard. It is therefore absolutely necessary to give the snowboard a dynamically correct shape at the manufacturing stage. This is achieved according to the invention by combining dimensions which are specific to the snowboard with selected features which are known to be employed in connection with skis, since these selected features together will give the snowboard an optimal dynamic adaptation. Thus it is the combination of the features indicated in the patent claims which make it possible to utilise the features known from skis for an improvement of an alternative product, viz. a snowboard.
There is therefore a fundamental difference between ski and board, and in the invention it has surprisingly been shown that by means of adaptation and modification of features known from the field of skis with regard to the design of twisted surfaces, it has been possible to develop a snowboard which is adapted to the dynamics which apply to skis.
When the tapered board according to the invention is placed on the snow, it can already have a better dynamic shape than the surface the board is capable of achieving, since the board according to the invention is produced with a twisting tapering of the sole adapted to where the weight is actually paced on the board, with regard to the ideal twisting tapering which is desired.
It has further been shown that there are significant safety aspects associated with a specific design of raised sliding surfaces with regard to landing after jumping with the snowboard. It is a fact that falls with snowboards result in many injuries, which are far more serious than the speed would indicate. The snowboard according to the present invention is also designed to increase safety in landing after a jump, due to the fact that it is not so aggressive in the edge area during landing.
The more curved the steel edge in the snowboard""s edge area is, the greater tendency it has to cut away in an uncontrolled fashion when landing after a jump, especially when making an almost flat landing. The invention will therefore provide greater safety benefits the more inward curve the snowboard has. By allowing the board to be almost flat along its entire width from the central portion a reasonable edge grip can also be secured when the board is flat against the snow. On the front and rear portions of the board the right and left parts of the sole are tapered upwards, thus providing a less aggressive steel edge, but at the same time the board has to be formed in such a manner that it has a good edge grip when turning. Thus a boat shape, in which the cross section shows curved lines near the steel edge will be unsuitable, since the angle at the steel edge will then be too large to give a good edge grip. The snowboard described with a cross section in the front and rear portions consisting of three straight lines (FIG. 2) will ensure both a less aggressive edge grip during landing after a jump and adequate edge rip during turning.
The width is a further significant difference between ski and snowboard. A narrow ski can easily be edged 45xc2x0. The much wider snowboard is usually run much flatter than a ski. A great deal of edge grip will therefore easily be lost with a snowboard when the secondary surfaces are too acutely angled relative to the first sole surface. The invention solves this special problem for snowboards by means of the special design of raised lateral area from the following criteria:
1. The secondary lateral area must have a certain minimum width which is greater than for most skis, thus achieving a greater uplift with less angling of the secondary lateral area relative to the first sole surface.
2. The secondary lateral area is raised from the plane of the main area by being tapered upwards when moving from the middle towards the tips.
3. The cross section shows the sole as three substantially straight lines in those parts of the board where there are secondary lateral areas.